Flameproofed textile fabrics and method therefor



United States Patent Oifice 3,507,688 Patented Apr. 21, 1970 Int. Cl.cimd /18 US. Cl. 117136 6 Claims ABSTRACT OF THE DISCLOSURE Flameproofedfabrics are prepared by applying to the fabric the reaction product of apolymer containing free anhydride groups, eg styrene-maleic anhydridecopolymer, and a tri(halogenalkyl)phosphate, e.g.tri(bromopropyl)-phosphate.

The present invention relates to fiameproofed textile fabrics and amethod for fiameproofing textile fabrics and, in particular, floorcoverings which comprise synthetic fibres only, by contacting them witha high molecular weight polymer containing phosphorus.

The use of a great many compounds for fiameproofing synthetic mouldedmaterials or synthetic fibres or filaments has already been proposed.For example, difliculty volatile organic bromine compounds andhalogen-containing copolymers have been used for this purpose.

These known products do not, however, satisfy all the requirements whicharise in connection with flameproofing of textiles. The use offiameproofing agents must not increase the attraction of the textile todirt, and they must not be removable by vacuum cleaning, shampooing, ordry cleaning, and they must be resistant to abrasion. Furthermore, theymust not affect detrimentally the physical properties of the filamentsor fibres and in particular their mechanical strength.

It is an object of this invention to provide improved fiameproofedtextile fabrics, especially from synthetic fibres, used as floorcovering and curtaining material, said fiameproofed textile fabricsbeing treated with a reaction product of a polymer containing acidanhydride groups with a halogen-containing phosphoric acid ester.

A further object of this invention is a method for flameproofingtextiles, in particular floor coverings and curtaining material whichcomprises treating the textile fabrics with a flameproofing agentconsisting of a reaction product of polymers containing acid anhydridegroups with halogen-containing phosphoric acid esters, as flameproofingagents and drying the treated textiles at temperatures from about 25 C.to about 130 C.

The phosphorus-containing and halogen-containing polymers which are usedin the method according to the invention are prepared in known manner byreacting copolymers containing acid anhydride groups with phosphoricacid esters which contain halogen atoms. Copolymers which may be usedinclude those obtained by copolymerisation of aryl-alkyl compounds whichmay also contain halogen, e.g. styrene, ot-methylstyrene,o-methylstyrene, m-propylstyrene, 2,4-dimethylstyrene, ethylene,propylene, butylene, alkyl benzenes, with unsaturated acid anhydridessuch as maleic acid anhydride or citraconic acid anhydride. Thecopolymers so formed may have a molecular weight of 10,000 to 80,000,preferably about 30,000. The halogenated phosphoric acid esters used arepreferably tri(halogenalkyl)-phosphates, such as tri-(chloroethyl)-phosphate, tri(dichloroethyl) phosphate,

tri (trichloropropyl) phosphate, tri(dichlorobutyl -phosphate,tri(bromoethyl)phosphate, tri(dibromoethyl)- phosphate ortri(dibromopropyl)phosphate.

The reaction may be carried out in organic solvents or aqueous emulsionsat elevated temperature, or by taking mixtures of the components inorganic solvents or aqueous emulsions, evaporating off the solvents andreacting the undiluted products on the surface of shaped articles toform elastic films which are insoluble in water and organic solvents.Shaped textile materials, such as fibres of natural or synthetic origin,for example polyamide, polyacrylonitrile, polyester, cellulose and woolfibres and textile products manufactured from them, especially floorcoverings and curtains, are rendered fiameproof by the treatment withthe high'molecular weight phosphorus-containing polymeric reactionproducts. In general, the phosphorus and halogen-containing reactionproducts are applied from organic solvents or aqueous emulsions. Thetreated textiles have the additional advantage that they repel dirt to agreater extent than untreated textiles. Another advantage of thephosphorusand halogen-containing reaction products is that after theyhave undergone complete reaction, the finish they produce is resistantto washing, cleaning, in particular using vacuum cleaners, shampooingand abrasion and vacuum cleaning, and in the case of floor coverings itis removed by constant wear by being walked over.

In contrast to known compounds that have flame inhibiting properties,the polymers used in the process according to the invention areparticularly effective even when applied in small quantities. Thepolymers are most effective when used in quantities of only 3% to 15%,preferably 4% to 6%.

The following examples illustrate more particularly the invention.

EXAMPLE 1 Tufted carpets of polyacrylonitrile and 20% polyamide fibres(weight of pile about 1 kg./m. are sprayed with 300 ml./m. of a solutionwhich was prepared as follows:

g. of tri(2,3-dibromopropy1)phosphate are dissolved in acetone togetherwith 33.3 g. of a polymer of styrene and maleic acid anhydride ofmolecular weight about 30,000 and the solution is made up to 1 litre.The solution so obtained is then heated for 3 hours at 60 C. 6.7 g. ofplasticiser, such as the monostearic acid ester of tri-p-hydroxyethylammonium formate and 6.8 g. of an ethoxylated stearyl alcohol and 5 ml.of water are then added to the cooled solution with stirring.

After removal of the solvent by evaporation, and after drying for 24hours at room temperature, a vacuum cleaner which has a beating actionis passed over the carpet at a rate of 3 minutes per m. The carpet whichhas been spray treated undergoes change in neither colour nor handle.The percentage reduction in brightness of the treated carpet aftersoiling is found to be 22.7%. The corresponding value for untreatedmaterial is 22.4%. As a result of carrying out the flammability testaccording to DIN 51 960 (cellulose-ethanol test), the treated goods areclassified as non-inflammable. The untreated carpet burns. When anattempt is made to ignite the carpet with a Bunsen burner, it is foundthat the carpet is difficult to ignite and is self-extinguishing.

EXAMPLE 2 Tufted capets of 100% polyacrylonitrile pile (weight of pileabout 1 kg/m. are sprayed with 300 ml./m. of an emulsion which wasprepared as follows:

86.5 g. of tri-(2,3-dibromopropyl)phosphate are added to 223 g. of a12.9% solution in ethyl acetate of a polymer of styrene and maleic acidanhydride of molecular weight about 20,000, this solution containing 28g. of the polymer, and the solution is kept at boiling point for onehour. 5.7 g. of plasticiser, e.g. the monolauric acid ester oftri-fl-hydroxyethyl ammonium formate, 5.7 g. of an antistatic agent,e.g. a dodeeylammonium compound, and 10 g. of emulsifier, e.g. benzylhydroxydiphenylpolyglycol ether, are then added. 350 ml. of water arestirred into the solution by hand, a further 350 ml. of water is added.The mixture is then agitated with a high speed stirrer for one minute.

The sprayed carpets are dried in a drying cupboard at 80 C. for onehour, or at room temperature for 48 hours. A vacuum cleaner with abeating action is then passed over the carpet at the rate of 1 sq.m./min. The carpet is unchanged in colour and handle after thistreatment. The percentage reduction in brightness of the sprayed carpetafter soiling which is obtained is 24.1%. The reduction obtained foruntreated goods is 23.8%. As a result of carrying out the flammabilitytest, the treated carpet is classified according to DIN 51 960(celluloseethanol test) as non-inflammable. Untreated goods burn. In theignition test using a Bunsen burner both from the side and fro-m above,the carpet is found to be inflammable only with difficulty and to beself-extinguishing.

EXAMPLE 3 Velour fabric made of polyacrylonitrile fibre is contacted ina padding machine adjusted to give 100% squeeze-out with an aqueousemulsion containing 84.4 grams/litre of the reaction product describedbelow. The velour fabric is then dried on a tentering frame at atemperature of 110 C. for a contact time of 1.5 minutes. The combustionperiod of the material, measured in an arc combustion testing apparatus,is then 105 seconds, and the flame extinguishes after a total combusionpath of 180.

The emulsion used was prepared as follows:

173 g. of tri-(2,3-dibromopropyl)-phosphate are added to 223 g. of a 26%ethyl acetate solution of a polymer of styrene and citraconic acidanhydride of molecular weight 15,000, which solution contains 59 g. ofthe polymer, and the reaction mixture is boiled for 1% hours. 6.2 g. ofplasticiser, e.g., the monostearic acid ester oftrifl-hydroxyethylammonium formate, g. of a dodecylammonium compound andg. of emulsifier, e.g. o-benzyloxy-diphenylglycol ether, are then added.358 ml. of H 0 are stirred into the solution by hand, and, after theaddition of a further 358 ml. H O the solution is agitated using a highspeed stirrer for 1 minute. The emulsion prepared in this way was thendiluted to 3 litres with water and was used for application in a paddingmachine.

EXAMPLE 4 Curtain fabric of polyacrylonitrile fibre is contacted in apadding machine adjusted to a squeezing effect of 100% with an aqueousemulsion which contains 100.5 grams/ litre of the reaction productdescribed below. The fabric is then dried on tentering frames at 110 C.for a contact time of 1.5 minutes. The combustion period of thematerial, tested in an arc combustion apparatus, is then 92 seconds andthe extinction takes place at Untreated fabric burns over the totalcombustion path of The emulsion used was prepared as follows:

213.6 g. of tri-(dichloropropyl)-phosphate are added to 223 g. of asolution in' ethyl acetate of polystyrene maleic acid anhydride ofmolecular weight 20,000, which solution contains 112 g. of the polymer.The solution is heated for one hour at 80 C. 9 g. oftri-fi-hydroxyethylammonium formate monododecyl ester is used asplasticiser, together with 5 g. of an antistatic, e.g. a dodecylammoniumcompound, and 10 g. of emulsifier, e.g. obenzyloxy-diphenylpolyglycolether, and 400 g. of water are then stirred by hand into the viscoussolution. The solution is then made up to 1 litre with water andagitated using a high speed stirrer for one minute. 1 litre of theemulsion prepared in this way is diluted with water to 3 litres and usedin the manner described above.

What we claim is:

1. Flameproof textile fabrics containing 3 to 18% by weight of thetextile fabric of a fiameproofing agent comprising:

(A) the reaction product of a copolymer having a molecular weight of10,000 to 80,000 and containing acid anhydride groups, with (B) anamount of tri-(halogenalkyl)-phosphate effecting to impart fiameproofqualities to said textile.

2. Flameproof textile fabrics ofclaim 1, wherein said halogenatedphosphoric acid ester is a tri-(halogenalkyl)- phosphate. 1

3. Flameproof textile fabrics of claim 1, wherein said copolymer is acopolymer of styrene and maleic acid anhydride having a molecular weightof about 20,000.

4. The flameproof textile fabrics of claim 1 wherein the weight ratio ofcopolymer and phosphate in the flameproofing agent is in the range of1:3 to 3: 1.

5. A method for fiameproofing textile fabric comprising:

(1) applying to the fabric an organic solvent solution or an aqueousemulsion of a flameproofing agent comprising;

(A) the reaction product of a copolymer having a molecular weight of10,000 to 80,000 and containing acid anhydride groups, with (B) aneffective amount of tri-(halogenalkyl)-phosphate; and

(2) drying the fabric; said flameproofing agent comprising 3 to 18% byweight of said fabric.

6. The method according to claim 5, wherein said treating is carried outwith an emulsion of the reaction product.

References Cited UNITED STATES PATENTS 2,660,543 11/1953 Walter et al.117136 MURRAY KATZ, Primary Examiner T. G. DAVIS, Assistant Examiner US.Cl. X.R. 117138.8, 161

